Multiple semiconductor dies may be mounted in a single package in one of two ways. Firstly, two or more semiconductor dies may be arranged next to one another in a horizontal direction along a substrate. Secondly, multiple semiconductor dies may be mounted on top of one another in a vertical direction, i.e. packaging the semiconductor dies into a chip-on-chip (COC) structure (‘COC packaging method’).
The COC packaging method includes preparing a bottom semiconductor die having a plurality of bond pads and a top semiconductor die having a plurality of bond pads. The bond pads of the bottom semiconductor die are interconnected to the bond pads of the top semiconductor die using conductive bumps. An underfill is injected into a gap between the bottom semiconductor die and the top semiconductor die. Bond pads formed around the circumference of the bottom semiconductor die are connected to a circuit board through conductive wires.
In the COC packaging method, a problem may occur in that an excessive flow of the underfill in the circumferential direction of the bottom semiconductor die may occur during injection. The underfill may cover the bond pads formed around the circumference of the bottom semiconductor die thus making it impossible for the wires to be bonded to the bond pads.
Therefore, a need existed to provide a system and method to overcome the above problem.